Nichola: keeping up with the jones is rarely a good idea. you need to do what you need to do because it is the right thing and for no other reason. if going to a grammar school is right for your daughter then you need to take responsibility and help her to prepare sufficiently. If it can be done in conjunction with her primary school then that is best but if not you must do what it takes. as for the homework set by the school being not sufficiently demanding, you should take this as a warning and set her work that is. in the middle of my son's year five I woke up to the fact that the maths being set was too simple when comparing it with the demands of the 11+ maths paper. I then took the view to teach him maths myself that was at the appropriate level and I do not regret it. there is plenty of guidance in these forums and on this website of what you can/should do.
Alexmonster: aaah Harry Potter. Personally speaking I am not a Potter fan but I also recognise the books are well written. If your son is reading this then be thankful and encourage him. I had a similar challenge when I found my son was obsessed with reading Alex Rider books rather than my beloved children's classics. In the end we decided to encourage him to read what he was interested in, while trying to broaden (sometimes by stealth) his horizons. We felt this was the right decision. The idea of children being tutored for the 11+ from a very early age at the expense of other considerations seems to me fairly horrific and, likely, counterproductive. I do believe though you should take steps (discussed in my book and elsewhere): a year before the exam you embark on a program to help prepare him (assuming that going to a grammar school is right for your son and what you as a family want to). I sympathise with your quandary though that while on one hand he is bright that on the other he is reluctant to study and suspect this is not uncommon, although I notice you are having some success. Without knowing your sitaution, it is difficult to comment, but I would say that in principle that you should encourage him to appropriately prepare in a regular, disciplined way, with you as the main educator (helped by tutors if you can/want) and at the same time to help him lead a happy, normal and balanced life.